- any dark intrusive rock in which dark minerals occur both as phenocrysts and as groundmass.
Origin of lamprophyre
1885–90; lampro- (< Greek lamprós clear) + -phyre
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for lamprophyre
In Fergus County, Montana, they are mined from decomposed dikes of lamprophyre (a basic igneous rock).The Economic Aspect of Geology
C. K. Leith
Each variety of lamprophyre may and often does contain all four minerals but is named according to the two which preponderate.
It is supposed that they did not crystallize in the lamprophyre dike but in some way were caught up by it.
They are found mostly as loose crystals in gravel, but are known also in igenous rocks like andesite and lamprophyre.
- any of a group of basic igneous rocks consisting of feldspathoids and ferromagnesian minerals, esp biotite: occurring as dykes and minor intrusions
C19: from Greek lampros bright + -phyre, from porphyry
- A dark igneous rock, having a porphyritic texture in which both the phenocrysts (larger crystals) and the matrix consist primarily of pyroxene, hornblende, and biotite.
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